I complete Christ?!

Further thoughts on the Incarnation....

Mom and I are (working on) memorizing the first chapter of Colossians. We were going over the verses on our walk yesterday morning (or was it the day before?), up to verse 23. Then we read ahead to get an idea of where we'd be going next.....and discovered this:

" I am now rejoicing in my suffereings for your sake, and in my flesh I am completing what is lacking in Christ's afflictions for the sake of his body, that is, the church. (v. 24)

Completing what is lacking in Christ's afflictions????????? This is saying, in other words, that Christ's suffering on the cross is incomplete...and we have what it takes to complete it?
And in John 15.....there's a vine and a branch. Apart from the vine, the branch dies - but can a vine bear much fruit without the branch?

If I weren't reading it directing out of my Bible, I might call this heresy! But I am...and it's not.

I (can) complete Christ...the Incarnation. God - almighty creator and ruler of the universe, omnipotent, omnipresent (and all the other "omni's"!) - needs me. Not because he is weak, incompetent, or otherwise incapable...but because this is how he chooses to love me. By involving me in this mystery of the Incarnation - even making me indispensable to the "project"!

Can this be true.....or am I having delusions of grandeur?